internal static void AnalyzeInvocation(SyntaxNodeAnalysisContext context)
{
var invocationExpressionSyntax = (InvocationExpressionSyntax)context.Node;
CSharpCommonInterest.InspectMemberAccess(
context,
invocationExpressionSyntax.Expression as MemberAccessExpressionSyntax,
Descriptor,
CommonInterest.JTFSyncBlockers,
ignoreIfInsideAnonymousDelegate: true);
}
private void InspectMemberAccess(
SyntaxNodeAnalysisContext context,
MemberAccessExpressionSyntax?memberAccessSyntax,
IEnumerable <CommonInterest.SyncBlockingMethod> problematicMethods,
INamedTypeSymbol taskSymbol)
{
if (memberAccessSyntax == null)
{
return;
}
// Are we in the context of an anonymous function that is passed directly in as an argument to another method?
var anonymousFunctionSyntax = context.Node.FirstAncestorOrSelf <AnonymousFunctionExpressionSyntax>();
var anonFuncAsArgument = anonymousFunctionSyntax?.Parent as ArgumentSyntax;
var invocationPassingExpression = anonFuncAsArgument?.Parent?.Parent as InvocationExpressionSyntax;
var invokedMemberAccess = invocationPassingExpression?.Expression as MemberAccessExpressionSyntax;
if (invokedMemberAccess?.Name != null)
{
// Does the anonymous function appear as the first argument to Task.ContinueWith?
var invokedMemberSymbol = context.SemanticModel.GetSymbolInfo(invokedMemberAccess.Name, context.CancellationToken).Symbol as IMethodSymbol;
if (invokedMemberSymbol?.Name == nameof(Task.ContinueWith) &&
Utils.IsEqualToOrDerivedFrom(invokedMemberSymbol?.ContainingType, taskSymbol) &&
invocationPassingExpression?.ArgumentList?.Arguments.FirstOrDefault() == anonFuncAsArgument)
{
// Does the member access being analyzed belong to the Task that just completed?
var firstParameter = GetFirstParameter(anonymousFunctionSyntax);
if (firstParameter != null)
{
// Are we accessing a member of the completed task?
ISymbol invokedObjectSymbol = context.SemanticModel.GetSymbolInfo(memberAccessSyntax.Expression, context.CancellationToken).Symbol;
IParameterSymbol completedTask = context.SemanticModel.GetDeclaredSymbol(firstParameter);
if (EqualityComparer <ISymbol> .Default.Equals(invokedObjectSymbol, completedTask))
{
// Skip analysis since Task.Result (et. al) of a completed Task is fair game.
return;
}
}
}
}
CSharpCommonInterest.InspectMemberAccess(context, memberAccessSyntax, Descriptor, problematicMethods);
}